Suppose that Y is a noise-corrupted observation of a signal S. That is, Y = S + N, where S is independent of N. Assume that for a known σ, N ∼ N(0, σ2) and S ∼ N (0, θ2), where θ is unknown. Given the observation Y = y:
(a) Obtain the MLE, θˆML.
(b) Obtain an EM algorithm.